From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net ([212.227.15.18]:58458 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932132AbcE2KxI (ORCPT ); Sun, 29 May 2016 06:53:08 -0400 Subject: Re: [PATCH v3 05/22] btrfs-progs: Introduce function to setup temporary superblock To: bo.li.liu@oracle.com, Qu Wenruo References: <1454043812-7893-1-git-send-email-quwenruo@cn.fujitsu.com> <1454043812-7893-6-git-send-email-quwenruo@cn.fujitsu.com> <20160528030459.GA31255@localhost.localdomain> Cc: linux-btrfs@vger.kernel.org, dsterba@suse.cz, David Sterba From: Qu Wenruo Message-ID: <9cd7dc82-184b-e5f0-0b7e-d359820202d2@gmx.com> Date: Sun, 29 May 2016 18:52:41 +0800 MIME-Version: 1.0 In-Reply-To: <20160528030459.GA31255@localhost.localdomain> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 05/28/2016 11:04 AM, Liu Bo wrote: > On Fri, Jan 29, 2016 at 01:03:15PM +0800, Qu Wenruo wrote: >> Introduce a new function, setup_temp_super(), to setup temporary super >> for make_btrfs_v2(). >> >> Signed-off-by: Qu Wenruo >> Signed-off-by: David Sterba >> --- >> utils.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 117 insertions(+) >> >> diff --git a/utils.c b/utils.c >> index bc10293..ed5476d 100644 >> --- a/utils.c >> +++ b/utils.c >> @@ -212,6 +212,98 @@ static int reserve_free_space(struct cache_tree *free_tree, u64 len, >> return 0; >> } >> >> +static inline int write_temp_super(int fd, struct btrfs_super_block *sb, >> + u64 sb_bytenr) >> +{ >> + u32 crc = ~(u32)0; >> + int ret; >> + >> + crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc, >> + BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); >> + btrfs_csum_final(crc, (char *)&sb->csum[0]); >> + ret = pwrite(fd, sb, BTRFS_SUPER_INFO_SIZE, sb_bytenr); >> + if (ret < BTRFS_SUPER_INFO_SIZE) >> + ret = (ret < 0 ? -errno : -EIO); >> + else >> + ret = 0; >> + return ret; >> +} >> + >> +/* >> + * Setup temporary superblock at cfg->super_bynter >> + * Needed info are extracted from cfg, and root_bytenr, chunk_bytenr >> + * >> + * For now sys chunk array will be empty and dev_item is empty >> + * too. >> + * They will be re-initialized at temp chunk tree setup. >> + */ >> +static int setup_temp_super(int fd, struct btrfs_mkfs_config *cfg, >> + u64 root_bytenr, u64 chunk_bytenr) >> +{ >> + unsigned char chunk_uuid[BTRFS_UUID_SIZE]; >> + char super_buf[BTRFS_SUPER_INFO_SIZE]; >> + struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf; >> + int ret; >> + >> + /* >> + * We rely on cfg->chunk_uuid and cfg->fs_uuid to pass uuid >> + * for other functions. >> + * Caller must allocation space for them >> + */ >> + BUG_ON(!cfg->chunk_uuid || !cfg->fs_uuid); >> + memset(super_buf, 0, BTRFS_SUPER_INFO_SIZE); >> + cfg->num_bytes = round_down(cfg->num_bytes, cfg->sectorsize); >> + >> + if (cfg->fs_uuid && *cfg->fs_uuid) { >> + if (uuid_parse(cfg->fs_uuid, super->fsid) != 0) { >> + error("cound not parse UUID: %s", cfg->fs_uuid); >> + ret = -EINVAL; >> + goto out; >> + } >> + if (!test_uuid_unique(cfg->fs_uuid)) { >> + error("non-unique UUID: %s", cfg->fs_uuid); >> + ret = -EINVAL; >> + goto out; >> + } >> + } else { >> + uuid_generate(super->fsid); >> + uuid_unparse(super->fsid, cfg->fs_uuid); >> + } >> + uuid_generate(chunk_uuid); >> + uuid_unparse(chunk_uuid, cfg->chunk_uuid); >> + >> + btrfs_set_super_bytenr(super, cfg->super_bytenr); >> + btrfs_set_super_num_devices(super, 1); >> + btrfs_set_super_magic(super, BTRFS_MAGIC); >> + btrfs_set_super_generation(super, 1); >> + btrfs_set_super_root(super, root_bytenr); >> + btrfs_set_super_chunk_root(super, chunk_bytenr); >> + btrfs_set_super_total_bytes(super, cfg->num_bytes); >> + /* >> + * Temporary btrfs will only has 6 tree roots: >> + * chunk tree, root tree, extent_tree, device tree, fs tree >> + * and csum tree. >> + */ >> + btrfs_set_super_bytes_used(super, 6 * cfg->nodesize); >> + btrfs_set_super_sectorsize(super, cfg->sectorsize); >> + btrfs_set_super_leafsize(super, cfg->nodesize); >> + btrfs_set_super_nodesize(super, cfg->nodesize); >> + btrfs_set_super_stripesize(super, cfg->stripesize); >> + btrfs_set_super_csum_type(super, BTRFS_CSUM_TYPE_CRC32); >> + btrfs_set_super_chunk_root(super, chunk_bytenr); >> + btrfs_set_super_cache_generation(super, -1); >> + btrfs_set_super_incompat_flags(super, cfg->features); >> + if (cfg->label) >> + strncpy(super->label, cfg->label, BTRFS_LABEL_SIZE - 1); > > Why not use __strncpy_null? > > Thanks, > > -liubo Good idea, I'll add new patch to use it. Thanks, Qu > >> + >> + /* Sys chunk array will be re-initialized at chunk tree init time */ >> + super->sys_chunk_array_size = 0; >> + >> + ret = write_temp_super(fd, super, cfg->super_bytenr); >> +out: >> + return ret; >> +} >> + >> /* >> * Improved version of make_btrfs(). >> * >> @@ -230,6 +322,10 @@ static int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg, >> struct cache_tree *used = &cctx->used; >> u64 sys_chunk_start; >> u64 meta_chunk_start; >> + /* chunk tree bytenr, in system chunk */ >> + u64 chunk_bytenr; >> + /* metadata trees bytenr, in metadata chunk */ >> + u64 root_bytenr; >> int ret; >> >> /* Shouldn't happen */ >> @@ -260,6 +356,27 @@ static int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg, >> if (ret < 0) >> goto out; >> >> + /* >> + * Inside the allocate metadata chunk, its layout will be: >> + * | offset | contents | >> + * ------------------------------------- >> + * | +0 | tree root | >> + * | +nodesize | extent root | >> + * | +nodesize * 2 | device root | >> + * | +nodesize * 3 | fs tree | >> + * | +nodesize * 4 | csum tree | >> + * ------------------------------------- >> + * Inside the allocated system chunk, its layout will be: >> + * | offset | contents | >> + * ------------------------------------- >> + * | +0 | chunk root | >> + * ------------------------------------- >> + */ >> + chunk_bytenr = sys_chunk_start; >> + root_bytenr = meta_chunk_start; >> + ret = setup_temp_super(fd, cfg, root_bytenr, chunk_bytenr); >> + if (ret < 0) >> + goto out; >> out: >> return ret; >> } >> -- >> 2.7.0 >> >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >